Sim card is not supported anymore? I want a solution

Note message that appears when I insert my sim card

Unsupported SIM card

The SIM card currently installed in this iPhone is from a carrier that is not supported under the activation policy currently enforced by the activation server. This is not a hardware issue with the iPhone. Please install another SIM card from a supported carrier or request that your carrier lift the restriction on this iPhone. Please contact Apple for more information. Try again.